Organic Light-Emitting Diode (OLED) has characteristics of complete solid-state, active lumination, high brightness, high contrast, slim and lightweight, low power consumption, no viewing angle limitations, wide operating temperature range and the like, and is considered to be leading technology for the next-generation flat panel display.
A key problem currently suppressing the development of the OLED industry is the life of the OLED device. A lot of tests and analysis shows that the main reason for the failure of the OLED device is the micro-electrolytic cell failure model of the OLED device. Specifically, the OLED device is a device driven by DC current, and if there is moisture inside the device, a micro-electrolytic cell will be formed inside the device and an electrochemical reaction will take place when the OLED is in an operating state. The thus-generated reaction gas will separate the metallic cathode from the organic functional layer which leads to the failure of the device. Moreover, a conventional OLED device usually adopts a metallic cathode of aluminum which is a relatively reactive metal and is susceptive to react with the infiltrated moisture so as to form a dielectric layer having a very large resistance, which is equivalent to connecting a large resistor in series inside the device and affects the brightness of the device. In addition, moisture and oxygen will also react with the organic materials, and such chemical reactions will also lead to the failure of the device. Therefore, research on the packaging of organic light-emitting device is of great significance to improve the efficiency of the device and to prolong the life of the device.
At present, a method for packaging the OLED is to use various types of epoxy resin and/or inorganic material to form a sealed adhesive layer after curing by UV light. Although such a sealing method is usually capable of providing good mechanical strength, it fails to provide sufficient capability of isolating moistures in most environments.